lipoteichoic-acid and Necrosis

To investigate the cooperative effect of Bifidobacteria lipoteichoic acid (BLTA) combined with 5-fluorouracil on tumor cells growth and apoptosis in mice bearing H22.. Hepatoma-22 (H22) cells were cultured in RPMI1640. Establish tumor-bearing mice model of liver cancer by injecting intraperitoneally 1×10(6)/mL cells into the above-mentioned Balb/c mice. 5-FU alone, BLTA alone or BLTA in combination with 5-FU were used to treat tumor-bearing mice. The tumor size were observed and measured regularly. The growth-inhibiting rate (IR) of tumor was detected. Real-Time PCR and Western blot were used to detect Bcl-2, Bax and Caspase-3 expressions of mRNA and protein in tumor tissue of tumor-bearing mice. Detection of apoptotic cells in tumor tissue by HE staining analysis. Detection of the organ index was for evaluate the added-activity of immune organs in mouse. FCM was used to detect T subgroup ratio of spleen cells of tumor-bearing mice. Expression change of mRNA and proteins of Foxp3 and TIM-3 were detected by Real-Time PCR and Western blot in tumor-bearing mice tumor tissue.. BLTA and 5-FU significantly inhibited the proliferation of tumor and induced obvious apoptosis, the combined effects were greater than those of the individual agents (P<0.01). The underlying molecular mechanism of apoptotic process could be up-regulation of Bax and down-regulation of Bcl-2 and Caspase-3. The HE staining indicated that combined treat could both induce tissue cells necrosis and increase immune cells infiltration. Organ index showed that BLTA can enhance the proliferation of immune organs. The ratio of CD4(+)CD25(+) Treg significantly decreased and CD4(+) T cell increased in BLTA and 5-FU group (P<0.01). Compared to NS group, mRNA and proteins expression of Foxp3 and TIM-3 down regulated in BLTA and 5-FU group (P<0.01).. These results show that combined effects of Bifidobacteria lipoteichoic acid and 5-FU on H22 cells were superior to the individual. The combination did not only increase anti-tumor effect, but also could alleviate the side effects of chemotherapy, with inhibiting TIM-3/TIM-3L pathway, cutting down immunosuppressive activity of CD4(+)CD25(+) Treg and enhancing cell-mediated immunity.

Topics: Animals; Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Bifidobacterium; Carcinoma, Hepatocellular; Caspase 3; Cell Line, Tumor; Cell Proliferation; Female; Fluorouracil; Forkhead Transcription Factors; Hepatitis A Virus Cellular Receptor 2; Immunity, Cellular; Lipopolysaccharides; Liver Neoplasms; Mice; Mice, Inbred BALB C; Necrosis; Neoplasm Proteins; Neoplasm Transplantation; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Receptors, Virus; RNA, Messenger; Spleen; T-Lymphocytes; Teichoic Acids

The bacterium Bacillus anthracis causes the death of macrophages, which may allow it to avoid detection by the innate immune system. We found that B. anthracis lethal factor (LF) selectively induces apoptosis of activated macrophages by cleaving the amino-terminal extension of mitogen-activated protein kinase (MAPK) kinases (MKKs) that activate p38 MAPKs. Because macrophages that are deficient in transcription factor nuclear factor kappaB (NF-kappaB) are also sensitive to activation-induced death and p38 is required for expression of certain NF-kappaB target genes, p38 is probably essential for synergistic induction of those NF-kappaB target genes that prevent apoptosis of activated macrophages. This dismantling of the p38 MAPK module represents a strategy used by B. anthracis to paralyze host innate immunity.

Topics: Animals; Antigens, Bacterial; Apoptosis; Bacterial Toxins; Calcium-Calmodulin-Dependent Protein Kinases; Carrier Proteins; Cell Line; Enzyme Activation; Enzyme Inhibitors; Gene Expression; I-kappa B Kinase; Imidazoles; Lipopolysaccharides; Macrophage Activation; Macrophages; MAP Kinase Kinase 3; MAP Kinase Kinase 6; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Necrosis; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyridines; Teichoic Acids; Transcription Factor RelA

Tumor necrosis factor (TNF) and IL-1 are thought to mediate many of the pathophysiologic changes of endotoxemia and Gram-negative bacteremia. In these studies, heat-killed Staphylococcus epidermidis were infused into rabbits to determine whether an endotoxin (LPS)-free microorganism also elicits cytokinemia and the physiologic abnormalities seen in Gram-negative bacteremia. S. epidermidis induced complement activation, circulating TNF and IL-1, and hypotension to the same degree as did one-twentieth the number of heat-killed Escherichia coli. Circulating IL-1 beta levels had a greater correlation coefficient (r = 0.81, P less than 0.001) with the degree of hypotension than TNF levels (r = 0.48, P less than 0.02). Leukopenia, thrombocytopenia, diffuse pulmonary capillary aggregation of neutrophils, and hepatic necrosis with neutrophil infiltration were observed to the same extent after either S. epidermidis or E. coli infusion. However, S. epidermidis infusion did not induce significant (less than 60 pg/ml) endotoxemia, whereas E. coli infusion resulted in high (11,000 pg/ml) serum endotoxin levels. S. epidermidis, E. coli, LPS, or S. epidermidis-derived lipoteichoic acid (LTA) induced TNF and IL-1 from blood mononuclear cells in vitro. E. coli organisms and LPS were at least 100-fold more potent than S. epidermidis or LTA. Thus, a shock-like state with similar levels of complement activation as well as circulating levels of IL-1 and TNF were observed following either S. epidermidis or E. coli. These data provide further evidence that host factors such as IL-1 and TNF are common mediators of the septic shock syndrome regardless of the organism.

Topics: Animals; Complement Activation; Escherichia coli; Hemodynamics; Interleukin-1; Leukocytes, Mononuclear; Lipopolysaccharides; Liver Diseases; Necrosis; Rabbits; Shock; Staphylococcus epidermidis; Teichoic Acids; Tumor Necrosis Factor-alpha